March- Dormant Oil season
Dormant oil can prevent insect damage to your landscape from bugs emerging in spring. Dormant oil needs to be applied when the temperature is above 5 degrees and no chance of freezing usually in March. It needs to be applied when the trees are still dormant, before they open their leaves. The oil works by smothering overwintering insects or insect nymphs by sealing them against air. It works better in some years than others, depending on the weather. The oil can damage the leaves of any tree if it’s applied after they start to unfold and the trees come out of dormancy early. Dormant oil is somewhat less harmful to beneficial insects than other insecticides.
